Effect of Signal Coordination on the Traffic Operation of Urban Corridor
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Abstract
The severity of traffic congestion has increased in Baghdad city and influenced the public’s perception of the community. Extended travel time is experienced by users of the urban street system, so optimal traffic operation with a coordinated traffic signal system becomes necessary. Also, it is needed to alleviate congestion and progress traffic movement along the urban corridor. This study aims to evaluate and optimize traffic signal timing for selected intersections on Palestine arterial corridor and apply the coordinated signal system to reduce the users’ travel time on the selected urban corridor. Analyzing and evaluating congested signalized intersections using Synchro (ver.9) (Al-Nakhala intersection, Al-Sakhra intersection, and Beirut intersection) were performed. Also, their adopted strategies for improving traffic performance and reducing delays were provided. The overall assessment in terms of the level of service for the current traffic states is (LOS F) with an average control delay of (197.2, 166.8, and 262.3) sec/veh. for the Al-Nakhala, Al-Sakhra, and Beirut intersections respectively. The queue length appears after two cycles, becoming more severe congestion at intersections under oversaturated traffic conditions. The performance operation efficiency improved by reducing the control delay from (197.2 to 88) sec/veh, (166.8 to 46) sec/veh, and (262.3 to 76) sec/veh for the Al-Nakhala, Al-Sakhra, and Beirut intersections respectively. Even at high volume and oversaturated conditions, the blocked intersections were effectively alleviated. Finally, it was observed that the proposed signal coordination, built on standard actuated control significantly performed along the urban corridor, reducing vehicles’ delay. However, there are still concerns regarding the flow-to-capacity ratio (v/c ratio is still greater than 1), and the level of service is still in poor conditions (LOS E) for Beirut and (LOS F) for Al-Nakhala intersections. The application of signal coordination improved traffic progression by reducing travel time, and vehicle delay and alleviating blocked intersections.
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References
Hummer JE, Reid JD. "Unconventional Left-Turn Alternatives for Urban and Suburban Arterials: An Update". Transportation Research E-Circular, 2000.
Transportation Research Board (TRB). "Highway Capacity Manual: HCM 2000". TRB, Washington, DC, USA, 2000.
FHWA (Federal Highway Administration). Signalized intersections: Informational guide. U.S. Department of Transportation, Federal Highway Administration, Washington, DC, USA, Rep. FHWA-HRT-04-091, pp 219–276, 2004.
Traffic ware. “Synchro Studio 8: Synchro plus SimTraffic and 3D Viewer". Traffic ware, Ltd., Sugar Land, TX, USA, 2011.
Lu S, Liu X, Dai S. “Revised MAX BAND model for bandwidth optimization of traffic flow dispersion”. In: ISECS international colloquium on control and management proceedings, 2008.
Lin LT, Huang HJ. An effective interval of traffic signal coordination under safety and efficiency considerations. Journal of the Chinese Institute of Engineers 2010; 33(2): 271-285. DOI: https://doi.org/10.1080/02533839.2010.9671617
Li W, Tarko AP. Effect of arterial signal coordination on safety. Transportation Research Record 2011; 2237(1): 51–59. DOI: https://doi.org/10.3141/2237-06
Qi H. Graphical solution for arterial road traffic flow model considering spillover. IEEE Access 2017; 6:6755–6764. DOI: https://doi.org/10.1109/ACCESS.2017.2786217
Ghiasi A, Hussain O, Qian ZS, Li X. A mixed traffic capacity analysis and lane management model for connected automated vehicles: a Markov chain method. Transportation Research Part B: Methodological 2017; 106 :266-292. DOI: https://doi.org/10.1016/j.trb.2017.09.022
Yang Z, Feng Y, Liu HX. A cooperative driving framework for urban arterials in mixed traffic conditions. Transportation Research Part C: Emerging Technologies 2021; 124:102918. DOI: https://doi.org/10.1016/j.trc.2020.102918
Naghawi H, Al Soud A, Al Hadidi T. The Possibility for Implementing the Superstreet Unconventional Intersection Design in Jordan. Periodica Polytechnic a Transportation Engineering 2018; 46(3) 122–128. DOI: https://doi.org/10.3311/PPtr.11635
Zhang G, et al. Assessing the impacts of signal coordination on the crash risks of various driving cohorts. Journal of Safety Research 2019; 70 :79-87. DOI: https://doi.org/10.1016/j.jsr.2019.05.003
Chang X, Li H, Rong J, Zhao X. Analysis on traffic stability and capacity for mixed traffic flow with platoons of intelligent connected vehicles. Physical A: Statistical Mechanics and Its Applications 2020; 557 :124829. DOI: https://doi.org/10.1016/j.physa.2020.124829
Alkaissi ZA. Traffic simulation of continuous flow intersection with displaced left-turn: a case study. Journal of Engineering and Applied Science 2022; 69(1):39. DOI: https://doi.org/10.1186/s44147-022-00091-7
Tian Z, Urbanik T, Messer C, A System Partition Approach to Improve Signal Timing, Transportation Research Board, Washington, D.C., CD-ROM, 2003.
Ma D, Xiao J, Song X, Ma X, Jin S. A back-pressure-based model with fixed phase sequences for traffic signal optimization under oversaturated networks.IEEE Transactions on Intelligent Transportation Systems 2021; 22(9): 5577–5588. DOI: https://doi.org/10.1109/TITS.2020.2987917
Ding H, Di Y, Feng Z, Zhang W, Zheng X, Yang T. A Perimeter Control Method For A Congested Urban Road Network With Dynamic And Variable Ranges. Transportation Research Part B: Methodological 2022; 155:160–187. DOI: https://doi.org/10.1016/j.trb.2021.11.008
Morgan JT, Little JDC. Synchronizing Traffic Signals For Maximal Bandwidth. Operations Research 1964;12(6):896–912. DOI: https://doi.org/10.1287/opre.12.6.896
Little JDC. The Synchronization Of Traffic Signals By Mixed-Integer Linear Programming. Operations Research 1966; 14(4): 568–594. DOI: https://doi.org/10.1287/opre.14.4.568
Alkaissi ZA. Travel Time Prediction Models and Reliability Indices for Palestine Urban Road in Baghdad City. Al-Khwarizmi Engineering Journal 2017; 13(3):120-130. DOI: https://doi.org/10.22153/kej.2017.01.007
Alkaissi ZA. Analytical Study of Headway Time Distribution on Congested Arterial: A Case Study Palestine Road in Baghdad City. International Congress and Exhibition Sustainable Civil Infrastructures: Innovative Infrastructure Geotechnology, pp: 85-97, 2019. DOI: https://doi.org/10.1007/978-3-030-01911-2_8
Alkaissi ZA, Hussain RY. “Delay Time Analysis and Modelling of Signalised Intersections using Global Positioning System (GPS) Receivers”. IOP Conf. Series: Materials Science and Engineering 671, 2020. DOI: https://doi.org/10.1088/1757-899X/671/1/012110